First Light: A new telescope means a new beginning

Photonstopper
First light image of Messier 57: The Ring Nebula. For the occasion, only 60 light frames and 30 dark frames, 15 seconds each frame, were captured and stacked. Affinity Photo 2 was used to create the stack and Pixelmator Pro for editing. M57 is a planetary nebula in constellation Lyra and was formed during the death throes of a Sun-like star.

We had been considering what our next step might be in outfitting the observatory with a more-or-less permanently mounted telescope. Would a very long focal length Cassegrain suit our needs? Both the C11 SCT and the Vixen Modified Cassegrain were available, already on hand but both had issues. After struggling with collimation on both telescopes, we were leaning toward a high-quality refractor as the solution. Long focal length on a refractor, though, means a long tube and we have limited space. The incident that damaged the Vixen pretty much forced our hand. Frustrated with collimation issues, and telescope repairs we doubt we could perform, we made the decision to go with a new refractor.

What ultimately steered us toward Askar and helped ease some (not all) doubt concerning focal lengths was the wonderfully high quality image of the “daytime Moon” we had captured with the smaller Askar 103APO — images with that level of quality can be cropped to make up for some lack of focal length. Watching YouTube reviews of some Askar’s bigger telescopes offered further assurance we were headed in the right direction.

The new Askar 151PHQ telescope installed on the observatory’s pier. At the eyepiece end is a ZWO ASIAir Plus computer and ZWO Automatic Electronic Focuser. We anticipate moving the computer to a different location on the telescope as cable management becomes a priority.

Inside doubled shipping boxes, the telescope was delivered in a solid transport case, packed in form-fit dense foam padding. The case is very high quality, very heavy, and bears multiple hand grips; it will now be set aside, stored some place against the day the telescope is taken out of service for some reason. If the case was an optional item, in our case we aren’t sure we would want it.

The Askar 151PHQ is doubtless the highest-quality telescope we have ever owned or used. It is a quadruplet astrograph, featuring a 151mm (six inch) aperture and a 1057mm focal length for an f/7 focal ratio, and designed to produce flat field images without add-on optics.

Taking advantage of a rare, relatively clear night, we went for first light using the big instrument with minimal configuration: no finder scope, no automatic tracking, no camera cooling, etc. While we had installed the ZWO AEF purchased years ago, and the ASI AirPlus, we used them only for manual electric focusing which, by the way, was a big improvement in itself! The optional hand controller was a wonderful thing to have, allowing us to watch through the eyepiece or on the computer screen and make smooth, minute adjustments to focus without telescope vibration. Yes, wonderful!

Under Bortle 6/7 skies pinpoint stars shown brightly through the eyepiece as we focused on Arcturus, then searched for M57. Our hazy skies, made worse by light pollution (maybe a Bortle 8 night), didn’t make things easy but with a little patience, a tiny, ghostly ring appeared in the field of view. We swapped out the eyepiece for the one-shot color camera, refocused, and began the imaging run. While we have much to learn about processing deep sky objects, we were happy to see the quality of the resulting stacked image: round stars and lots of them (many more stars than we’re used to seeing there), good detail in the ring, and decent color — all in 60 light, and 30 dark 15-second frames. The Moon eluded us that night, still down in the trees at midnight, but we tried solar first light the next morning.

First images of our Sun via the Askar 151PHQ were recorded under poor seeing conditions but, with some work, produced some pretty impressive results. A TeleVue Powermate 2.5X Barlow was employed here. We hope to refine our setup for the new telescope for better edge-to-edge focus. The telescope was equipped with a Baader white light solar film filter and monochrome camera; false color applied during processing.

Placing a Baader Solar film filter over the Askar’s objective and aiming the scope at Sun, we quickly saw beautiful detail in the sunspots that marked the surface on July 31. Imaging was routine and easy, though seeing was poor. The telescope’s 1,057mm focal length did not allow a full disk image of our star on the ASI astronomical camera’s sensor but installing a Barlow lens we achieved some dramatic detail views. We can hardly wait to try again under better skies!

Long focal length produces a Solar image too large to entirely fit on the astronomy camera’s sensor. With quality like this, however, we won’t complain. This is Sun on July 31, 2026, imaged via white light solar filter and monochrome camera, false color applied during processing.

Nearly too large! When observing low elevation targets, the telescope fits snugly within the observatory walls. Fortunately, the tall pier and large mount elevate the assembly enough that normal observing is at a comfortable height and (M57 was at the zenith during First Light!) high elevation targets do not cause us to lay on the floor or scrape the camera there! We suspect this scope on a tripod might present some problems for high elevation object observing.

Thus far the only negative, something unanticipated, is that because of the Petzval design, an optical element is located deep within the OTA making use of our beloved Herschel Wedge a risk to the telescope; that optical element is at a point in the light path where focused and unfiltered sunlight could overheat and damage the lens! We’re working around it and will assign the Herschel to the Askar 103 when desired. As we anticipated, we’d love to have much more focal length but without collimation to worry about and high quality images to work with, we’ll hope to get by … maybe with the help of a really good Barlow lens?

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